Lessons learned from spatiotemporal effect of COVID on the population density in the CBD

Alonso in 1964 developed the land use and transport interaction theory based on the bid and rent concept. It tells that the central core part of urban areas has the highest housing rental prices, and it gradually decays as it is further away from the centre. The city's district is divided based on the distribution of land prices according to distance from the city centre. This fundamental relationship provides a basic insight into how people behave rationally subject to their living budgets. Based on this relationship, this paper aims to investigate the temporal and spatial changes in the de facto population of Seoul caused by coronavirus disease 2019 (COVID-19). The de facto population has declined significantly since 2020. A major decrease has been found in areas within 2.5 km of travel distance from the city centre. The de facto population decreased the most during the night hours (18:00-24:00) on weekdays and the daytime (10:00-18:00) on weekends. These findings could be postulated to foresee how people might select their housing locations in terms of transport costs in the post-COVID-19 era.